Question

If 317. 7 coulombs was used in an electrolytic cell, how many grams of zn would we expect to be plated from a zn2 solution onto an electrode?

Answer 1

Answer: The amount of Zn plated from a solution is 1.07×$10^{-1}$ grams.

Explanation: In this question, it is given that of 317.7 coulombs was used in an electrolytic cell, i.e,

The amount of charge = 317.7 coulombs

The amount of charge of 1 mole of electrons = 96485.3 coulombs   ( FARADAY’S CONSTANT )

Now,    the number of electrons = amount of charge given / charge of 1 mole of electrons

            The number of electrons =  $\frac{317.7}{96485.3}$  =   $3.29$×$10^{-3}$

According to reaction occurring, 2 moles of electrons are required to convert 1 mole of   to Zn which is plated on the electron, so the moles of Zn plated will be half the moles of electrons, i.e.,

                                                          $\frac{3.29*10^{-3} }{2}$     =  1.645×$10^{-3}$

Now, we know that the molar mass of zinc is 65.38gm/mole,

          Number of moles = mass in grams / molar mass

          Mass in grams = number of moles × molar mass

          Mass in grams =  (1.645×$10^{-3}$) × 65.38  =  0.1075 gm.

Conclusion: It concludes that the amount of Zn plated from a 1.07×$10^{-1}$  solution is  gm.